Lorena Sun: Geochemical signatures of continental weathering in deep-sea corals

Glacial meltwater can potentially affect the biogeochemical cycle in adjacent coastal waters. The Arctic, a region particularly sensitive to changing climate, owes its largest glacial meltwater input from the Greenland ice sheets. The Greenland ice sheet has waxed and waned with oscillating climate affecting albedo, sea level, ocean circulation, and nutrient input to coastal waters. However, the rate and amplitudes of ice sheet changes response to intervals of rapid climate change require further study. A useful test case is the last millennium when the Northern hemisphere experienced warming and cooling events known as the Medieval Warm Period (∼AD 800–1200) and the Little Ice age (∼AD 1350–1850). Here I report geochemical records (uranium isotopes, rare earth elements and yttrium) of modern and fossil cold-water corals from Nuuk, western Greenland over the warming at the end of the Little Ice Age. This well-dated deep-sea corals archive provides a unique window to probe the ocean’s response to meltwater input during millennial climatic events. The results are consistent with enhanced weathering of continental material during this climate transition,  indicative of enhanced release of basal meltwaters from the ice sheet.  

Maddie Reader: Damage to jet engines by airborne particulates; Detection and mitigation

Volcanic ash is an aerosol capable of causing both short and long term impacts for aviation around the globe. Short term impacts include flights which have experienced total engine failure due to ash ingestion, whereas longer term impacts include the “no fly zone” being implemented across Europe during the 2010 eruption of Eyjafjallajökull. Therefore, it is important to understand the effect ash particulates have on jet engines. The variation in ash composition, along with particle size and distribution, can have a significant effect on how it is deposited within the engine. These variables can be tested in engine simulation experiments which involve heating ash to the operating temperature of a jet engine in a jet flame and firing it onto both a metal target which is either uncoated or treated with a thermal barrier coating. Other research aspects will involve designing a small on-wing device which could be used to gather in-situ measurements, helping pilots to determine whether they are flying through volcanic ash that may previously have been undetected.

Zoom link: https://bristol-ac-uk.zoom.us/j/96309344441